Effect of earthworm population on survival and abundance of white grubs in different habitats

Monday, November 17, 2014: 10:24 AM
C124 (Oregon Convention Center)
Sudan Gyawaly , Department of Entomology, Virginia Tech, Blacksburg, VA
Curt A. Laub , Department of Entomology, Virginia Tech, Blacksburg, VA
Thomas P. Kuhar , Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA
White grubs (Coleoptera: Scarabaeidae) cohabitate with many other micro- and macro fauna in the soil environment. The interspecific relationships between many of those organisms and white grub populations have not been well studied.  In particular, very little is known about the influence of earthworms on white grub populations.  In Virginia in 2014 we conducted several laboratory and field studies to help us better understand the relationship between earthworm populations and white grub populations. Field surveys were conducted to determine the relationship between earthworm density and white grub density in turf and pastures. A laboratory experiment was carried out to determine whether earthworms could transport the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana in the soil from one location to another.  A follow-up experiment was carried out to test the effect of earthworm presence on the efficacy and infection rates of entomopathogenic fungi on white grubs in the soil. The results of the study are discussed.